Vacuum pump



Oct-22, 1935. A. M. BABlTcH l 2,018,111"

VACUUM PUMP Filed April 23, 1952 2 sheets-sheet 1 A. M. BABITCH Oct. 22, 1935.

VACUUM PUMP Filed April 25, 19:2

z'sheets-sheet 2 Patented oci. 22, 193s PATENT OFFICE.

. VACUUM: PUDIP -Abraliam M. Babitch, Flint, Mich., asignar to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application April Z3, 1932, Serial No. 607,130 2 (Cl. 230-170) 'I'his invention relates to pumps and has been designed to serve as an air pump. More particularly it is intended to operate as a subatmospheric or vacuum pump for the purpose of actuating 6 mechanism such as a windshield cleaner.

An object of the invention is to provide a simple form of pump mechanism which may be operated by an engine such, for example, as the engine of a motor vehicle, to withdraw air from any source such as thechamber of a Windshield cleaner motor and to discharge the air to any region desired such as the intake manifold of the engine.

Another object. of the invention is to introduce a cushioning bumper in the instrumentality by whichthe engine' operated plunger reciprocates the pumping member.

Another object is to mount the reciprocating plunger relative to the' pump mechanism in such a way that it may be retained when the pump is removed from the engine.

Other objects and advantages will be understood from the following description.

In the drawings accompanying the following description- Fig. 1 is a view in side .elevation partly in sec'- tion of sucha pump installed on a motor vehicle. Fig. 2 is avertical transverse section through the pump substantially on the lines designated as 2-2 of Fig. 3.

Fig.`3 is a view as seen from line 3-*3of Fig. i, parts being broken away andvshown in section.

Fig.-4 is a view as seen' from line 4 4 of Fig. 2 with parts broken away. I

Fig. 5 is a section on line 5-5 of Fig. 4 on a larger scale. l

Fig. 6 shows in perspective parts of the pump mechanism in disassembled relation.

Fig. '1 is a view as seen from line 1--1 of Fig. 3.

Referring by reference characters to the4 drawings, numeral 1 represents the engine of a motor vehicle, the vehicle being equipped with a conventional windshield as vShown at 9. At i i is illustrated the motor for a vacuum-operated windshield cleaner equipped with an oscillating cleaner blade. Communicating with the chamber vof the motor i I is a pipe I3 which is tobe connected with the pump at its opening l1 as shown on Fig. 2. From the outlet I9 of the pump a pipe 2i may be connected to a suitable discharge chamber, such a chamber being the inlet manifold 23 in the embodiment of the invention illustrated in the drawings. i

The engine is equipped with a shaft 25 which maybe a shaft constituting an operative part of the engine such, for example, asthe camshaft.

lThis shaft l25 may project from the end of the engine block and be provided with an eccentric operating means 21, this eccentric being designed to reciprocate-the movable member of the pump.

A The pump preferably includes two major parts 5 one or bothof which may be conveniently formed v by die casting. Part 29 constitutes the base portion of the pump and is formed with a ange 3l which is to be secured to a suitable support conl stituting a part of the engine, the support being 10 positioned adjacent the end of shaft 25. The flange 3| is fastened by suitable fastening means This first-mentioned part 29 is formed with a tubular projection 35 for the reciprocation o f a plunger 31, the lower end of which is to be en- 15 gaged by the eccentric 21. The upper end of the plunger 31' is reduced in diameter and on the shoulder formed by such reduction is received a shallow cup or spring retainer 39. A suitable spring`4l engages withinthis cup 39. duced portion of the plunger 31 andslightly above the spring abutment 39 is a ring 32.- 'I'his ring may engage the cup 39 to prevent the passage of the plunger through thecup. Furthermore, the diameter of the cup is greater than the diameter A25 of the opening 35 so that by means of the construction described the pump plunger may not fall from the pump when the pump is removed from its support. Also, in the base of the member 29 there is provided an opening 26 which open ing communicates with a passage 28 through the pump support and permits, the return of any oil to the crankcase which may have passed the plunger 31. Y

The second die cast member is designated 6I and is the major part of the pump. It has an annular flange 43 which is clamped to ange 45 of the member 2Q by fastening means 41. Between the flanges 43 and 45 and secured by the fastening means @il is a diaphragm 49. This diaphragm is preferably non-metallic and to its central portion there are secured upper and lower metal discs 5I and 53. These discs are secured by rivets 55. On the underside of the diaphragm and disc 53 and also secured by the rivets 55 is an 45 open cup 51 housingbut exposing'a cushion or f bumper 59 of resi-lient material, such as rubber.l Surrounding the cup 51 and in abutment withv the retainer 39 and the flange of cup 51 is the spring #il referred to above. Y

From the'iiange 43 ofthe upper pump member 6I rises a side wail 63 in which are the oppositely located openings i1 and l9.jY At the base of the wall 63 is a transverse partition 65. The cavity between the underside of the partition and the 55 On the re- 20v upper side .of the diaphragm 49 constitutes the ,pump chamber. Rising from the bottom of the ing between the walls 61 and 63. This wall is,

in height, substantially equal to the height of Wall '63, but of less height than the inner wall 61- whereby the latter with the closure 69 rises above the top of wall 63. r

From the radial wall 11 the space between the Walls 63 and 61 is unoccupied for the greater part of the annular. region between these walls.

This open segmental chamber terminates at 19 where the casting is made solid above the parti- I tion 65 substantially equal to the height of wall 63. The opening I1 communicates with this segmental annular chamber. Just beyond the region 19 the casting, in the annular region between the walls, is of less height than portion 19 as shown by numeral 8|. A screen 83 covers the region between the walls 63 and 61, resting on` a ledge at the top of wall 63, on the top of the radial wall 11, and on a ledge formed by making a shoulder as at 85 on the wall 61. A cap 81 overlies the top of member 6I and is secured to the top of wall 63 by suitable fastening means, the screen being held in position as stated since its marginal portion lies betweemthe flange of the cap and the top of wall 63. The cap is of dome shape so that it'covers the closure portion 69 .above the wall 61 and provides a chamber above the screen. l

On its underside the partition 65 is recessed to'y receive a brass segmental plate 89 and a gasket 9|..

the solid portion 19 ofthe casting 6I This pocket is in combination with the outlet I9 as clearly shown in Fig. ,2. 'The metal of the plate 39 around the opening 95 is turned up to form a seat for a `valve 99 and above the valve is a spring I 0I which engages a cast-in member |05.r Member |05 has a central opening |03 and in addition thereto are otheropenings |01 affording communication between the pocket 91v and the region above the valve 99. In the region 8| there is an opening |09.

Seated in this opening is a valve seat I I I. Engagling the valve seat is-a valve vI I3 held by a spring II5 against its seat. The opposite end of the spring l I5 is in abutment with the central pore tionof a disc member II 1 which engages ,the

plate 89 and has an opening II8 concentric withy the opening 93. By the construction' described a valve communication is provided for the inlet' of gas from the region above the portion 8| to the pump chamber.

' yphragm on-its side remote from said chamber,

The plate 89 has two openings 93 and 95' l .of which the latter lies opposite a pocket .91 in It will be understood that the spring 13 is op- Yerable tol depress thediaphragm andV increase the capacity of the pump chamber thereby mak' ing a suction stroke. It willalso be seen that the plunger 31'operated bythe eccentric 21 raises 6 the diaphragm through its engagement with the resilient block 59 and thereby makes a discharge stroke. It will also be seen that the parts desig- -nated by numerals'32 and 39 prevent the escape the spring 13 and hold the diaphragm in an uppermost position. Under such circumstances the plunger 31 is free to reciprocate downwardly 20 when the eccentric 21 makes itsidle stroke. The spring 4 I functions then to hold the plunger 31 in contact with the eccentric andprevents the subsequent noise which would occur when the eccentric again engaged the plunger. When now the plunger is upwardly reciprocated by the eccentric to produce an upward reciprocation of the diaphragm, the engagement of the reduced end o! the plunger with the resilient bumper 59 permits such action to take place without noise. A

vIt will be observed that thescreen, engaging the top of parts 11 and 19, prevents air from entering the region above the inlet valve-prior to the removal of foreign matter.

I claim;

1. Inv a pump, a flexible diaphragm, means forming with said diaphragm, a pump chamber, a block of resilient material secured to said dial andra reciprocable plunger to operate said diaphragm through the yinstrumentality of'said re silient block, additional means to deliver to said diaphragm strokes of varying amplitude in the opposite direction whereby there occurs'a varying space relationbetween the plunger and the resilient block togetherwith a coil/spring surround ing said block and engaging said diaphragm and reciprocating plunger.

2. In a pump, a exible diaphragm, means .forming with said diaphragm a pumping chamber, mechanism on the side oi.' the diaphragrnfrelA 

